From the Guidelines
The workup for visual hallucinations in elderly patients should begin with a comprehensive medical evaluation to identify underlying causes, including a detailed history and physical examination, laboratory testing, neuroimaging, and cognitive assessment, as recommended by recent studies 1. The evaluation should focus on identifying potential causes of visual hallucinations, such as medication side effects, infections, metabolic disturbances, structural lesions, and neurodegenerative conditions like Lewy body dementia or Parkinson's disease with psychosis. Some key points to consider in the workup include:
- Medication review, as many drugs (particularly anticholinergics, dopaminergic agents, and benzodiazepines) can cause hallucinations 1
- Laboratory testing, including complete blood count, comprehensive metabolic panel, thyroid function tests, vitamin B12, folate levels, and urinalysis to rule out infections or metabolic disturbances
- Neuroimaging with CT or MRI of the brain to exclude structural lesions
- Cognitive assessment using tools like the Mini-Mental State Examination or Montreal Cognitive Assessment to evaluate for dementia
- Ophthalmologic examination to rule out Charles Bonnet syndrome (hallucinations due to vision loss), which is common in the elderly 1
- Consideration of EEG if seizure activity is suspected
- Identification and treatment of delirium, if present, as it can contribute to visual hallucinations 1 For neurodegenerative conditions like Lewy body dementia or Parkinson's disease with psychosis, medications like pimavanserin (34mg daily) or low-dose quetiapine (25-100mg daily) may be considered, while avoiding high-potency antipsychotics like haloperidol in elderly patients with parkinsonism 1. Visual hallucinations often result from disruptions in visual processing pathways or neurotransmitter imbalances, particularly involving dopamine, acetylcholine, or serotonin systems, which explains why addressing underlying medical conditions and carefully managing medications is crucial to effective treatment. It is essential to prioritize the patient's quality of life, morbidity, and mortality when making treatment decisions, and to consider the latest evidence-based guidelines and recommendations from reputable sources 1.
From the Research
Visual Hallucinations in Elderly Workup
Causes of Visual Hallucinations
- Visual hallucinations in the elderly can be due to a myriad of underlying causes, including organic brain disease, visual impairment, cerebrovascular disease, and Parkinson's disease 2, 3
- New onset visual hallucinations in the elderly are strongly suggestive of organic brain disease 2
- Visual hallucinations can be linked to disorders in multiple parts of the nervous system, including ophthalmological, vascular, or degenerative processes 3
Treatment of Visual Hallucinations
- Treatment of visual hallucinations is treatment of the underlying cause 3
- Some newer drugs such as clozapine may also be helpful for selected patients 3
- Amisulpride has been found to be efficacious in some cases of visual hallucinations, particularly in those associated with Charles Bonnet syndrome and vascular dementia 2
- Quetiapine and ziprasidone have been found to have faster decreases in mean hallucination scores compared to risperidone in some studies 4
Diagnostic Approach
- The clinician should assume that there is an organic basis when an elderly individual begins to develop visual hallucinations for the first time 3
- A thorough diagnostic workup should be conducted to rule out underlying causes such as cerebrovascular disease, Parkinson's disease, and other organic brain diseases 2, 3
- The possibility of coexisting delusional infestation (parasitosis) should also be investigated 5
Pharmacological Interventions
- Antipsychotic drugs such as risperidone, olanzapine, quetiapine, and ziprasidone may be effective in reducing hallucinations in some patients 4, 6
- However, the evidence for psychopharmacological interventions is scanty, and randomized controlled trials are lacking in the area 2
- Quetiapine may produce fewer parkinsonian effects than some other antipsychotic drugs, but may also lead to greater weight gain and cholesterol increase 6